1. Semiclaustral ant queens must pay the price of foraging to guarantee their survival and also that of their brood through the nest foundation phase. For leaf-cutting ant species, the challenge is even greater, as they also need to cultivate their symbiont fungus.2. We hypothesised that suppressing foraging activity could reflect in larger offspring and higher survival, as queens would be entirely dedicated to rearing the brood and initial fungus.3. By providing easy access to leaves or completely denying it, we evaluated how foraging runs interfere in Acromyrmex subterraneus queens' survival, productivity, and variation of body mass components.4. Three foraging conditions were simulated: Starved -no leaves, Spoiled -leaves inside the nest chamber, and Walker -leaves 3 m away from the nest chamber. We registered the number of dead queens, offspring, weight of the fungus garden, fresh and lean dry mass of the queens, as well as their lipid and water contents.5. Survival of Starved queens, which did not oviposit, was lower than that of Spoiled and Walker queens, although weight loss, water content, and lean dry mass were similar. While lipid content reduction was similar for Spoiled and Walker queens, the former had more larvae and pupae, and a heavier fungus garden than the latter, suggesting a greater rearing effort of Spoiled queens toward them both.6. The simulated foraging conditions provided novel data for a semiclaustral leaf-cutting ant species that evidences that fungus garden cultivation is definitively the main driving force for the colony founding success.

Revegetation programs are proposed to recover the soil and biodiversity of disturbed sites, this being the case of the Rio Doce basin, Brazil. This region was hugely affected by a mining waste dam disruption, whose leakage on the soil altered its chemical and physical characteristics, and consequently the physiology and performance of plants. The expected alterations of the plants can make them more attractive for leaf-cutting ants, as lower water content induces an increase of non-structural carbohydrates. In this context, we evaluated whether Acromyrmex subterraneus workers differentiate among plants grown on soil with different mining waste concentrations. Leaf disks from plants grown in soil containing 0, 25, 50, 75, and 100% of mining waste were simultaneously offered to workers from laboratory ant colonies. The number of transported disks from each mining waste concentration was recorded until all disks of any concentration had been transported. Leaf selection assays were repeated after 30 days due to the novelty effect phenomenon. Leaf thickness, water, starch, and total soluble carbohydrates (TSC) contents were determined. Leaf disks from plants grown in soil with 100% of mining waste concentration were preferentially selected in both selection assays. Leaf thickness and water content were significantly lower in plants from the aforementioned treatment, while starch and TSC were higher. Results suggest that seedlings implanted in sites with high mining waste concentration are under high predation risk. Revegetation programs must measure the impact of leafcutting ants as both herbivorous and soil ecosystem engineers, for the best management of these insects.